Re: GSoC - code of implementation of materialized views

Robert Haas napsal(a):
> 2010/6/25 Pavel Baros <baros(dot)p(at)seznam(dot)cz>:
>
>>> On http://github.com/pbaros/postgres can be seen changes and my attempt to
>>> implement materialized views. The first commit to the repository implements
>>> following:
>>>
>>> Materialized view can be created, dropped and used in SELECT statement.
>>>
>>> CREATE MATERIALIZED VIEW mvname AS SELECT ...;
>>> DROP MATERIALIZED VIEW mvname [CASCADE];
>>> SELECT * FROM mvname;
>>>
>>> also works:
>>> COMMENT ON MATERIALIZED VIEW mvname IS 'etc.';
>>> SELECT pg_get_viewdef(mvname);
>>>
>> ... also you can look at enclosed patch.
>>
>
> So, this patch doesn't actually seem to do very much. It doesn't
> appear that creating the materialized view actually populates it with
> any data; and the refresh command doesn't work either. So it appears
> that you can create a "materialized view", but it won't actually
> contain any data - which doesn't seem at all useful.
>
>

Yeah, it is my fault, I did not mentioned that this patch is not final.
It is only small part of whole implementation. I wanted to show just
this, because I think that is the part that should not change much. And
to show I did something, I am not ignoring GSoC. Now I can fully focus
on the program.

Most of the problems you mentioned (except pg_dump) I have implemented
and I will post it to HACKERS soon. Until now I've not had much time,
because I just finished my BSc. studies yesterday.

And again, sorry for misunderstanding.

Pavel Baros

> Some other problems:
>
> - The command tag for CREATE MATERIALIZED VIEW should return CREATE
> MATERIALIZED VIEW rather than CREATE VIEW, since we're treating it as
> a separate object type. I note that dropping a materialized view
> already uses DROP MATERIALIZED VIEW, so right now it isn't
> symmetrical.
> - Using "\d" with no argument doesn't list materialized views.
> - Using "\d" with a materialized view as an argument doesn't work
> properly - the first line says something like ?m? "public.m" instead
> of materialized view "public.m".
> - Using "\d+" with a materialized view as an argument should probably
> should the view definition.
> - Using "\dd" doesn't list comments on materialized views.
> - Commenting on a column of a materialized view should probably be allowed.
> - pg_dump fails with a message like this: failed sanity check, parent
> table OID 24604 of pg_rewrite entry OID 24607 not found
> - ALTER MATERIALIZED VIEW name OWNER TO role, RENAME TO role, and SET
> SCHEMA schema either fall to work or fail to parse (plan ALTER VIEW
> also doesn't work on a materialized view)
> - ALTER MATERIALIZED VIEW name SET/DROP DEFAULT also doesn't work,
> which is OK: it shouldn't work. But the error message needs work.
> - The error message "CREATE OR REPLACE on materialized view is not
> support!" shouldn't end with an exclamation point.
> - The parser token OptMater should probably be called OptMaterialized
> or opt_materialized, rather than abbreviating.
> - There are no docs.
> - There are no tests.
>
>